OAIster is a union catalog of digital resources. We provide access to these digital resources by "harvesting" their descriptive metadata (records) using OAI-PMH (the Open Archives Initiative Protocol for Metadata Harvesting).
This is a collection of bibliographies of scientific literature in computer science from various sources, covering most aspects of computer science. The bibliographies are updated weekly from their original locations such that you'll always find the most recent versions here.
o connect users to primary research content, by enabling publishers to work collectively. CrossRef is also the official DOI® link registration agency for scholarly and professional publications.
ChemSpider is a free access service providing a structure centric community for chemists. Providing access to millions of chemical structures and integration to a multitude of other online services ChemSpider is the richest single source of structure-base